Hawks are among the many predators that catch their prey by chasing it. Chasing takes both time and effort to make a successful capture. To be successful, predators that chase their prey must concentrate on species that will provide enough nutrition to offset the energy burned while chasing. This is one reason why the hawk tends to eat more rodents and birds than grasshoppers. Grasshoppers just don't provide enough food value to justify the effort it takes to catch them.
Herons use a different technique, the stalk. Standing motionless in shallow water or wading slowly along the shore, the heron patiently searches for prey. When a heron sees its prey it captures it with a quick lunge of its long, sharp beak. This method does not require much energy, so a stalking predator can afford to choose smaller prey and still meet its energy requirements. One downside is the amount of time it takes to search for food.
The alligator prefers to lie still and wait. This method of hunting requires little effort, but chances of getting food are low. Fortunately, the cold-blooded alligator has minimal energy requirements. It can get by with infrequent meals. Most ambush hunters are fairly small because a successful ambush depends on the predator avoiding detection until it strikes.
Some animals hunt in teams. Wolves, lions, hyenas, coyotes and killer whales will usually live and hunt in family teams. Not only can they pursue larger and sometimes faster prey, but family groups can protect their little ones from other large predators. There's even a tropical insect that hunts as part of a team. South American army ants travel together in the tens of thousands and devour every living thing in their path: insects, snakes, livestock, rats and mice. There aren't many creatures that can withstand marching army ants!
Vision is often the most important sense for a predator. A predator's eyes are usually located in front of its head. The forward location of the eyes offers an animal binocular-type vision. The area that each eye sees overlaps so the brain receives two slightly different messages about the same scene. This helps a predator determine how far away prey is. It also tells the predator how fast its prey is moving.
Birds and insects must have the ability to catch prey in the air. A bird of prey's telescope-like vision can be eight times stronger than ours. Some predators rely on more sets of eyes than just one! Spiders and scorpions have clusters of six to eight eyes. Some of the eyes form the image. Others estimate distance, and still others detect motion. Fun fact: It's amazing that, even with eight eyes, a spider can only see about 1 foot in front of its face!
Predators which hunt at night (nocturnal predators) have special mirror-like structures in the back of their eyes. These structures help the animal to see in the dark. Deep sea animals have the same structures.
Most predators have a very good sense of hearing. In mammals, external ear flaps can be swiveled forward or backward in order to pinpoint the direction of a sound. The ears of bats are often highly specialized, with strange shapes that help catch the echoes of the calls they make as they fly. Birds can hear very well, too. Owls are thought to have the most outstanding hearing of any animal. Their ears are offset, which means one is higher than the other.
This is another way to pinpoint the source of sound. Some animals don't need ears to hear. Instead, they rely on vibrations they feel in their bodies. On land, ground vibrations from moving prey animals are transmitted through the bones of salamanders and snakes to the nerves near their ears. In water, sharks can monitor vibrations with a lateral-line system. Fluid-filled canals lie just beneath the shark's skin along the sides of its head and body. The canals are filled with small pores open to the water. Underwater noises or motion cause a vibration that strikes these open pores. A shark can then tune into the vibration and hunt down its next meal.
Some predators can smell a meal from a mile away! Foxes are even able to smell food which is buried under two feet of soil. Some use their sense of smell to follow the footsteps or tracks of an animal.
A shark has outstanding smelling ability, but it works a bit differently. Their nostrils are not for breathing, but are used for sensing odor. Water flows in and out of the nostrils. A shark is able to identify the different smells found in the water. Amazingly, a shark can smell its prey from 2 miles away!
Snakes use their tongues to smell. You might see a snake flicking its tongue around. The snake is not getting ready to bite; it is smelling the air by picking up dust particles. These particles are carried to taste detectors in the snake's mouth. The taste tells snakes what animals are near.
These are used to help kill the prey and are used as "knives and forks" while eating the prey. Most animals have three kinds of teeth. In the front, you'll find incisors. These are used to cut food. On the sides, you'll see longer teeth which are used for tearing chunks of flesh off of the prey. Canine teeth can also be used to kill the prey by piercing the neck or throat. Molars are found towards the back of the mouth. They are flat and strong and used to chew or grind. Some animals, such as crocodiles and sharks, have long, cone-shaped teeth. These are used for grasping the prey and pulling it underwater. When underwater, the prey will drown, enabling the predator to eat it.
Jaws as well as teeth are important adaptations that enable predators to seize and subdue their prey. Powerful muscles provide leverage and gripping power at the front part of the jaws. Some snakes are able to unhinge their jaws. This allows them to swallow a meal that is much larger than the snake's own head!
In some cases, beaks take the place of teeth. Each beak tells a story about its owner. Long beaks are used for probing, hooked beaks for tearing, thick ones for crunching seeds, thin ones for picking insects. Beaks provide birds with a lightweight alternative to a mouthful of teeth — like hollow bones, they are an adaptation for flying.
Sharp claws are also powerful weapons. Birds of prey have powerful claws, called talons, which help them grab their prey. Most big cats have claws that they use to grip and tear. They are able to pull in these claws when walking or running. This keeps them sharp. Moles and hedgehogs use their claws to dig up insects. In the same manner, grizzly bears dig up roots and burrowing rodents. Of course, on the grizzly, the claws are on the "tip of the weapon." A grizzly's powerful paw can bring an animal down with one swipe.
Some predators use their tongue as an effective weapon. A chameleon has one of the fastest tongues. It shoots its sticky tongue, which is coated with a glue-like substance, out towards its prey to capture and help swallow it. Did you know anteaters have tongues as long as a person's arm? This adaptation helps an anteater to reach areas where he or she needs to reach.
Another hunting weapon is poison. Snakes use their poison, which comes from their fangs, to paralyze or kill their prey. A spider releases strong digestive enzymes that turn the prey's insides to liquid. A straw-like mouth enables the spider to suck up the liquid. Wasps and scorpions paralyze their prey by using powerful stingers. A jellyfish uses its deadly tentacles.
Nature provides many ways for animals to make themselves hard to see. Both predators and prey use camouflage. Prey use it to hide themselves from predators, and predators use it to keep their prey from knowing they're coming after them!
One type of camouflage is when an animal's coloring is similar to its surroundings. Now you know why desert animals are often brown and jungle animals are often green.
Another type is called counter-shading. A counter-shaded animal is darkest on the top of its body and lightest on the bottom. From a distance these animals seem to turn into one color and look flat.
A third type of camouflage is called disruptive coloration — this is patterns of strongly contrasting, non-repeating markings such as spots or stripes. A zebra has this type. Its stripes help it to hide when it is grazing near trees and bushes. Does a tiger have disruptive coloration? Why?
Here are some more camouflage stategies:
Some animals change color with the season. This helps them to blend in with their surroundings when their surroundings change.
Imitation, or mimicry, is another form of camouflage. This is when an animal looks like a member of another species or like an object in its environment, such as when a grasshopper mimics a dry leaf.
Bright coloration, which seems the opposite of camouflage, is another form of self-defense when used to warn animals to stay away. Brightly colored animals are often poisonous or have an unpleasant taste.